The present disclosure relates to a method of manufacturing a semiconductor device, a semiconductor device, and an electronic apparatus.
Electronic apparatuses such as a digital video camera and a digital still camera include a semiconductor device such as a solid-state imaging device. Examples of the solid-state imaging device include a CMOS (Complementary Metal Oxide Semiconductor) image sensor and a CCD (Charge Coupled Device) image sensor.
In the solid-state imaging device, plural pixels are arranged in the surface of a semiconductor substrate. Each pixel includes a photoelectric conversion element. The photoelectric conversion element is, for example, a photodiode and generates a signal charge by receiving light incident via an external optical system through the use of a light-receiving surface and photoelectrically converting the received light.
In solid-state imaging devices, in general, light incident from the surface of the semiconductor substrate on which circuits or interconnections are formed is received by the photoelectric conversion element. In this case, since the circuits or interconnections block the incident light, it may be difficult to improve photosensitivity. Accordingly, a “backside illumination type” has been proposed in which light incident from the rear surface opposite to the surface of a semiconductor substrate on which circuits or interconnections are formed is received by photoelectric conversion elements (for example, see Japanese Unexamined Patent Application Publication Nos. 2005-150463 and 2008-182142).
In a semiconductor device such as the solid-state imaging device, “three-dimensional mounting” has been proposed in which plural substrates having different functional elements formed thereon are stacked and are electrically connected to each other. In “three-dimensional mounting”, since optimal circuits corresponding to the functions are formed on the substrates, it is possible to easily realize an enhancement in the performance of the device. For example, a sensor substrate having sensor elements formed thereon and a logic substrate having logic circuits, which process signals output from the sensor elements, formed thereon are stacked to construct a solid-state imaging device. Here, pad openings are formed by penetrating the semiconductor substrate so as to expose the surface of a pad interconnection and the elements are electrically connected to each other via the pad openings. That is, the sensor substrate and the logic substrate are electrically connected to each other via a TSV (Through Silicon Via) (for example, see Japanese Unexamined Patent Application Publication No. 2010-245506).